Chlorine can be prepared in the laboratory by the reaction of hydrochloric acid and potassium permanganate.(b) Calculate E° and ∆G° for the reaction

Verified step by step guidance

1. insert step 1: Write the balanced chemical equation for the reaction between hydrochloric acid (HCl) and potassium permanganate (KMnO4).
2. insert step 2: Identify the half-reactions for the oxidation and reduction processes involved in the reaction.
3. insert step 3: Use standard reduction potentials (E°) from a table to find the E° for each half-reaction.
4. insert step 4: Calculate the overall standard cell potential (E°) for the reaction by combining the half-reaction potentials.
5. insert step 5: Use the equation \( \Delta G^\circ = -nFE^\circ \) to calculate the standard Gibbs free energy change (\( \Delta G^\circ \)), where \( n \) is the number of moles of electrons transferred and \( F \) is the Faraday constant.

Key Concepts

Standard Electrode Potential (E°)

The standard electrode potential (E°) is a measure of the tendency of a chemical species to be reduced, expressed in volts. It is determined under standard conditions (1 M concentration, 1 atm pressure, and 25°C). A positive E° indicates a greater likelihood of reduction, while a negative E° suggests a lesser tendency. This concept is crucial for understanding redox reactions and calculating the overall cell potential.

Gibbs Free Energy (∆G°)

Gibbs free energy (∆G°) is a thermodynamic quantity that indicates the spontaneity of a reaction at standard conditions. A negative ∆G° value signifies that a reaction can occur spontaneously, while a positive value indicates non-spontaneity. The relationship between E° and ∆G° is given by the equation ∆G° = -nFE°, where n is the number of moles of electrons transferred and F is Faraday's constant. Understanding this relationship is essential for predicting reaction feasibility.

Redox Reactions

Redox reactions involve the transfer of electrons between two species, where one is oxidized (loses electrons) and the other is reduced (gains electrons). In the context of the reaction between hydrochloric acid and potassium permanganate, identifying the oxidation states of the elements involved helps determine which species undergoes oxidation and which undergoes reduction. Mastery of redox concepts is vital for calculating E° and ∆G° accurately.